I can't answer all your questions, but I can help with some.
How thick is the fine silver layer assuming its done ten times as
mentioned? ie: how much repolishing will it take?
First, I repeat the process more like 4-5 times. I don't think I've
ever gone to ten or needed to!
Secondly, I don't know how thick the fine silver/gold layer is,
because I have no way of measuring it. However, if you try the heat
patination/patterning technique I described in a post yesterday,
you'll find that it takes some effort to remove the surface layers to
get down to the sterling; it requires more than a little sanding. If
you don't get down to the sterling, you'll get gray instead of black
when you do the final depletion.
As for the re-polishing... I don't. I use a brass bristle brush on
the flex shaft. If you want a mirror finish, you'll have to start
with one (before the depletion process) and then buff lightly and
quickly at the end. Again, the key is experimentation.
Do you quench in pickle or air cool first?
Quench in pickle while hot (but not red hot) for the most
efficient result. If you air cool first, it will just take longer.
How does gilding compare in a practical sense to silver-plating?
It seems to me gilding would take maybe half an hour?, whereas
plating about five minutes. Is there a superior finish with the
No, but... You need special equipment and chemicals to plate. Also,
to prevent plated sterling from showing firestain/tarnish in time,
you should nickel plate first, before plating with fine silver (or
rhodium, or whatever).
I think someone mentioned scrubbing with a brass brush, would that
not discolor the silver? How about a nickel or stainless steel
brush?(which I used in my silversmithing days to good result)
If you're talking about the brushing that's done between the
depletion repetitions, then it doesn't seem to matter. For the final
finish, however, I was told to use nickel on silver and brass on gold
though I could never see the difference when I occasionally slipped
up and used brass on silver. I don't believe you're brushing enough
to make a difference, but it may just be that my eyes aren't as
sensitive as others'.
I will look for a suitable chunk of scrap to experiment with,
might be fun.
That's the key! Hope you had fun :-).